CN1102357C

CN1102357C - A tobacco filter material and a method for producing the same

Info

Publication number: CN1102357C
Application number: CN95118621.3A
Authority: CN
Inventors: 浅井种美; 岛本周; 松村裕之; 柴田彻
Original assignee: Daicel Chemical Industries Ltd
Current assignee: Daicel Corp
Priority date: 1994-09-22
Filing date: 1995-09-22
Publication date: 2003-03-05
Anticipated expiration: 2015-09-22
Also published as: DE69527756T2; EP0706766A2; US5856006A; DE69527756D1; EP0706766A3; CN1482142A; CN1219797C; EP0706766B1; US6344239B1; CN1129089A

Abstract

A tobacco filter material containing fibers or particulate which have a core and a surface layer which surrounds the core, wherein the core comprises a non-esterified cellulose and the surface layer comprises a cellulose ester. The fiber or particulate may be (A) a cellulose fiber coated with a cellulose ester or (B) a fibrous cellulose derivative with its surface layer esterified by an organic acid and having an average degree of substitution of not more than 1.5. Wood pulp can be used as the cellulose fiber or particulate.

Description

The method of tobacco filtering material, tobacco filter and production tobacco filtering material

Technical field

The present invention relates to a kind of satisfied biodegradability that has, the tobacco filtering material of wet capacity of decomposition or further feature, a kind of method of producing this tobacco filtering material and a kind ofly guarantee that tobacco has the good aromatic odor and the tobacco filter of palatability when using filtering material.

Background technology

Has harmful constituent such as tar in effective removal tobacco as a kind of, and the tobacco filter of energy satisfaction guaranted smoking quality, known filtering plug is by making a kind of cellulose acetate (for example, a kind of have average substitution degree be about 2.4 cellulose acetate) fiber and a kind of plasticizer be shaped to tow (fibre bundle) as glyceryl triacetate and preparing.But this filtering plug, biodegradability are very low, and plasticized dose of the long filament that forms partly clinkering together, when causing being dropped after the smoking, filtering plug needs long time to decompose automatically in environment, has therefore increased pollution problem.And this filtering plug is difficult to reclaim fully to be disposed and will need the recovery cost of almost making us forbidding.Use the method for burning to handle filtering plug, will cause discharging a large amount of combustions heat and the serviceable bife of combustion furnace is significantly reduced.

Simultaneously, known also have from wood pulps be processed into sheet or crepe paper shape and the tobacco filter made and be the tobacco filter that raw material is made with the regenerated celulose fibre.Compare with the filtering plug of being made up of cellulose acetate fibre tow (cellulose), these filter tips have meritorious biodegradability and good slightly wet decomposability (wet disintegration ability), and therefore, what have the ability of polluting that reduces.But in these filter tips, not only aromatic odor of tobacco (sense of taste) and palatability are very poor, and compare with the cellulose acetate filter tip, they as tobacco filter the selectivity that must have to eliminate the ability of phenols very disappointing.In addition, fall on the basis at setting pressure, those filter-tip solidities or hardness are lower than the cellulose acetate filter tip.Moreover these flaky materials of being made by wood pulps have very low bulkiness, therefore, need give the higher bulkiness of material and fall lousiness or wearing and tearing and the low pressing mold processability that causes to reduce pressure.

Japanese Patent Application Publication No.45468/1978 (JP-A-53-45463) corresponding US application number No.730039 discloses a kind of filtering material and has been made up of the nonwoven sheet of the cellulose ester short fiber of cellulose esters fibrillation with high surface area that contains 5-35% weight and 65-95% weight.And this prior art is pointed out can mix wood pulps in the mixture of cellulose esters fibrillation and cellulose ester short fiber.But, because the fibrillation that cellulose esters is difficult to be converted into provides the fibrillation with high surface area to need special technique.And the capacity of decomposition of this filtering material and biodegradability are high not enough, so exist very big risk of pollution.

Japanese Patent Application Publication NO.141185/1980 (JP-A-55-141185) discloses and has a kind ofly sealed or bonding and filtering material that flaky composite material that make is formed by the sheet entity of mainly being made up of wood pulp cellulose with by the sheet entity that cellulose esters derivative fibre tow is formed.But, this filtering material, although how much improved the armaticity and the palatability of smoking, but when pressing mold sheet entity and sealing or bonding two, must use plasticizer such as glyceryl triacetate so that between the fiber and clinkering between the sheet, this just can not satisfy the requirement of wet capacity of decomposition.

In addition, sheet tobacco filtering material also can crease or other phenomenon in pressing mold or type-approval process once in a while, but needs this filtering material that grows tobacco to keep high dry strength in these processes or in the dry-cure process, and therefore, its wet decomposability is very low.Same making, though highly wet decomposability can be provided flaky material but its intensity is also very low under the dry-cure condition.

Simultaneously, Japanese Patent Application Publication No.227939/1993 (JP-A68-227939) discloses a kind of cigarette filter, and it is made by biodegradable aliphatic polyester with micropore, can reduce environmental pollution.How many this filter tips has improved biodegradability, but is to use the armaticity of this filter tip smoking to compare relatively poor with palatability with the cellulose acetate filter tip.

Japanese Patent Application Publication No.72900/1977 (JP-A-52-72900) discloses a kind of tobacco filter and has been made up of the fibrous acetyl fibre cellulose aggregate of average degree of acetylation between 10-50%.This piece document points out that fibrous acetylation of cellulose obtains by using acetylation catalyst such as sulfuric acid that cellulose fibre such as paper pulp are carried out acetylation.But,, can not satisfy the requirement of biodegradability though the fiber that obtains by this technology has good armaticity and palatability for tobacco when smoking.

The open NO.1944/1969 (JP-B-44-1944) of Japan Patent discloses a kind of tobacco filter, this is that a kind of method by dipping or spray adds the solution that contains hydrophobic polymer in paper, and gained paper is fixed to bar-shaped to increase the paper filter tip of its solidity and retractility (elasticity).Although the smoking quality of this tobacco filter increases, because the adding of hydrophobic polymer makes other component bonding or coating of the fiber or the paper of composition, this filter-tip wet decomposing force has been lost greatly.

Therefore, the outstanding feature of tobacco filter such as good smoking quality are efficiently removed the ability of harmful constituent, and high dry strength and high biodegradability and/or wet capacity of decomposition are difficult to comprehensively obtain in traditional tobacco filter.

Summary of the invention

Therefore, the purpose of this invention is to provide a kind of armaticity that does not reduce smoking, the sense of taste and palatability, have high biodegradability and therefore solved tobacco filtering material of pollution problem and preparation method thereof.

Second purpose of the present invention provides a kind of except having aforesaid outstanding characteristics, tobacco filtering material of harmful constituent and preparation method thereof in the tobacco in the time of can also guaranteeing effectively to remove smoking.

The 3rd purpose of the present invention provides and a kind ofly do not reduce the smoking quality and have fabulous wet decomposability and biodegradability and therefore reduced tobacco filtering material of environmental pollution burden and preparation method thereof.

The 4th purpose of the present invention provides a kind ofly to be had good dry strength but holds back tobacco filtering material of wet then very fast automatic degraded and preparation method thereof.

The 5th purpose of the present invention provides a kind of harmful components and tobacco filtering material with enough anti-suction (pressure drop) abilities in the tobacco when guaranteeing effectively to remove smoking.

The 6th purpose of the present invention provides a kind of tobacco filter with above-mentioned praiseworthy characteristics.

Inventor of the present invention has carried out concentrated further investigation for finishing above-mentioned purpose, notice material surface participation or relevant with the filter-tip smoking quality of raising, and find harmful components when using cellulose esters can not reduce the armaticity of smoking and palatability and can effectively remove smoking coating cellulose fibrous or that the special fiber element coating makes, and this filtering material is to meet that rainwater in water such as the natural environment just can decompose easily and is biodegradable.They also find, only fibrous or specific cellulose derivative surface esterification can not reduce the smoking quality (as, armaticity, the sense of taste, palatability), and in natural environment, demonstrate high degradability (capacity of decomposition).The present invention finishes on the basis of above-mentioned discovery.

Therefore, tobacco filtering material of the present invention is a kind of filtering material of being made up of fiber or particle, and they have a core and surround the superficial layer of described core, and described superficial layer is made up of cellulose esters and described core is made up of non-esterified cellulose.

In this fiber or particle, the cellulose esters in the superficial layer can with example be the organic acid esters that contains about 2-4 carbon atom, (for example, cellulose acetate).Non-esterified cellulose can be made up of wood pulp in core.Filtering material uses with the sheet type with round shape structure usually, but also can at random crumple or embossing.

Illustrate, fiber in filtering material or particle can be that (A) uses cellulose esters to coating cellulose fibrous or the special fiber element coating.The amount of coated cellulose esters can be selected in a big way in coating cellulose (A), for example, to wash a layer cellulose (A) total amount, is no less than 0.1 weight %.

Described fiber or particle also can be (B) a kind of fibrous or plain derivatives of special fiber that comes from natural or regenerated celulose fibre or particle development.They are made up of the superficial layer of core and encirclement core, and by fiber or the esterification part of particle formation superficial layer and the non-esterified part of core on esterification surface, and the average substitution degree of total cellulose derivative is no more than 1.5.

This coating cellulose (A), plain derivative of fibrous or special fiber (B) and the filtering material that contains the material of these compositions are biodegradable and can show, for example, according to ASTMD 5209-91 with the amount that discharges carbon dioxide as indication, measure 4 week degradation rate be not less than 20% of weight.

The ratio of filtering material floating coat cellulose (A) or fibrous or the plain derivative of special fiber (B) can be selected in a big way, for example, is no less than 30% of filtering material gross weight.

Tobacco filter of the present invention contains tobacco filtering material as mentioned above.

Described tobacco filtering material can use cellulose esters that fibrous or the plain face coat of special fiber are prepared by (A).Coating can be carried out like this, for example, use dipping, spray or other technologies make fiber or particle surface enclose or be stained with cellulose esters and the dry coating cellulose that obtains, or in the poor solvent of cellulose esters, add cellulose esters and mixture fibrous or that special fiber is plain, or dry this mixture of spray quinoline.

In addition, the cellulose derivative (B) of forming filtering material can for example, in liquid phase, use organic acid and organic acid acid anhydrides or halide to handle natural or regenerated celulose fibre or particle by with the acquisition of getting off.

The used term " sheet " of specification should be understood that to refer in particular to and have the pattern entity that two-dimensional expansion can be made into the cylinder shape herein.

In this specification, described " biodegradation " is meant in degraded or the decomposable process, and its each step all is degraded or the decomposition on the biology that carries out under the help of organism such as microorganism or its analog.

Filtering material of the present invention is made up of as component material aforesaid fiber or particle.

According to tobacco filtering material of the present invention, the fiber that the tobacco filtration is made contributions during to smoking or the surface of particle are made up of cellulose esters.Therefore, the filtering feature of this material is the same with the filter tip of being made up of cellulose acetate fibre good as the ability of tar with effective removal harmful substance as the smoking quality.Use still keeps the material of good pressing mold processability in enough pressure drops (anti-suction) condition.Therefore, filtering material of the present invention is made up of this fiber or particle, and their function is born respectively by superficial layer and core, it is characterized in that having both sides' advantage, promptly outstanding smoking quality and height biodegradability, and can fine each other coordination.

Fiber of the present invention or particle specifically, are coating cellulose (A) and/or cellulose derivative (B).

Coating cellulose (A) specifically describes as follows:

Cellulose can at random be a kind of native cellulose or a kind of regenerated cellulose.This cellulose comprises the wood pulp that gets from wood-fibred [for example, from cork (coniferous tree) or hardwood (broad leaf tree)], and seed fiber (for example, cotton such as gined cotton, kapok, kapok etc.), bast fiber is (for example, hemp, flax, jute ， Limonene fiber crops, the native cellulose that paper mulberry skin and mitsumata (Edgeworthia papyrifera) or leaf fiber (for example, Manila hemp and New Zealand hemp) obtain; Regenerated cellulose such as viscose rayon yarn, CUP and nitrate silk.The cellulose of these kinds can use separately or be used in combination.

These cellulosic forms are fibrous or a kind of given shape (for example, Powdered).Fibrous cellulose can carry out fibrillation.Cellulosic fibrillation technology is not difficult to, illustrate, this fibrillation can be by traditional approach as the making beating raw material to obtain cellulose, for example, use the beater making beating and the wood pulp that obtains.Can be further obtained refined cellulose (cellulose of microfibrillated) by the cellulose of fibrillation by allowing impact force action to carry out refinement treatment on it.

The fibre diameter of fibrous cellulose and fibre length can suitably be selected in not influencing as the scope of the required feature of filter tip, therefore, the diameter of fibrous fiber cellulose fiber does not have special qualification, and actual can be about 0.01-100 μ m, preferably about 0.1-50 μ m.Also there is no particular limitation for the length of fiber, can be the random length that can use, generally is about 50 μ m-10mm (for example, about 50-3,000 μ m), preferably about 100-2000 μ m.

The cross sectional shape of fibrous cellulose does not have special qualification yet, and passable example has circle, oval or other shape.Therefore, the cross section that fibrous cellulose can change (for example, Y-, X-, R-or I-type) or hollow.If necessary, fibrous cellulose can curl, but generally uses the non-crimping type.

The used cellulose of the present invention preferably uses fibrous, but specific (specially referring to Powdered) cellulose also can use.Specific cellulosic granular size can be selected in a big way under the condition that pressing mold processability (formability) and capacity of decomposition are had no adverse effect.Therefore, specific cellulosic mean particle size is about 0.1-600 μ m, preferably about 10-500 μ m, and 20-250 μ m more preferably from about.If mean particle size is less than 0.1 μ m, then this particle will be removed from material, and when particle greater than the going up in limited time of 600 μ m, then the material specific area that will lose surface flatness and material will reduce.

Preferred fibrous or specific cellulose comprises particularly wood pulp of wood-fibred.Conventional slurry can be used as this wood pulp, and the purity of slurry is not particularly limited.Therefore, any highly purified wood pulp that contains the alpha-cellulose more than 90% or 90%, or contain the wood pulp of hemicellulose of high concentration such as the rudimentary slurry of low-purity can use.Wood pulp can be at random cleaved, or use the method for pulling an oar with its fibrillation.Do or wet autofrettage (net-forming technology) is made this fibrillation slurry to obtain the sheet wood pulp by using.The degree of the making beating of wood pulp can fully be selected, and has the Canadian standard freeness value, that is, the value of beating degree is to use Canadian beating degree detectors measure, and scope is at about 100-800ml, practical application preferably about 150-700ml.In this wood pulp, increased interfibrous entanglement or interweaved, therefore, this wood pulp has the intensity of raising and high loft and has high wet decomposability.

Use cellulose esters in fibrous or specific cellulose surface coating to form coating cellulose.In this coating cellulose, the coated cellulose esters on a part of surface of fiber or particle at least, but coating cellulose need apply equably on its whole surface.

The characteristics of coating cellulose of the present invention (A), on the one hand, by cellulose esters on fibrous or surface-coated that special fiber is plain so that it can coordinate the various features as tobacco filter, as good smoking quality, outstanding biodegradability and wet capacity of decomposition.That is to say, in the tobacco filtering material, comprise coating cellulose (A), in that effect contributes or relevant fiber or particle surface are coated with and have been covered with cellulose esters to smoke filtration.Therefore, the filtering characteristic of this material is the same with the filter tip of being made up of cellulose acetate outstanding as the ability of tar with effective removal harmful constituent as the smoking quality.This material has and the same high biodegradability of the filter tip that is formed by wood pulp or regenerated cellulose simultaneously.In addition, coating cellulose can not use the condition dip mold or the typing of plasticizer, and therefore provides praiseworthy good wet capacity of decomposition.Moreover, coating fiber or particle have big surface area, therefore and have the ability of efficient removal harmful components, and make this material under enough pressure drops (anti-suction) condition, still keep good formability.

As the spendable example of cellulose esters organic acid esters such as cellulose acetate are arranged, cellulose propionate, cellulose butylate and analog thereof; Inorganic acid ester such as cellulose nitrate, cellulose sulfuric acid ester, cellulose phosphate etc., mixed acid ester such as cellulose acetate propionic ester, cellulose acetate butyrate, cellulose acetate phthalate ester and cellulose nitric acid acetate; The cellulose esters derivative is as the cellulose acetate of poly-second lactone grafting etc.These cellulose quinones can use separately or be used in combination.

As the raw material of cellulose esters, can use different celluloses such as above-mentioned illustrational cellulose natural or regeneration, for example wood pulp.The purity of wood pulp can be at random high or low.

The average degree of polymerization of cellulose esters (the average viscosity value of polymerization) can be about 10-1000 (for example, about 50-1,000), preferably about 50-900 (for example about 100-800) and 200-800 more preferably from about.When average degree of polymerization is too small, filtering material will be lost mechanical strength, prescribe a time limit when average degree of polymerization is higher than, then not only mobile and pressing mold processability, and also the biological degradability of filtering material also can be lost.

The average substitution degree of cellulose esters can be selected in the scope of about 1-3.But be construed as, have average substitution degree in about 1-2.15 scope, other cellulose esters of level of preferred 1.1-2.0 is useful to improving biodegradability.Simultaneously, the filtering material of use coating cellulose of the present invention (A) is 2.0-2.6 even it is characterized in that the average substitution degree of employed cellulose esters, and it also can provide high biodegradability.

In the cellulose quinone, the equivalent proportion of residue alkali metal or alkaline-earth metal and residual sulfuric acid is about 0.1-1.5, during preferably about 0.3-1.3 (for example, about 0.5-1.1), has outstanding hear resistance and biodegradability.Sulfuric acid is from deriving as the sulfuric acid of catalyst when preparing cellulose esters and coming.Sulfuric acid not only comprises free acid, also comprises the sulfate of staying in the cellulose esters, sulfosalicylic acetate and sulfuric ester.Alkali metal (as, lithium, sodium, potassium, etc.) and alkaline-earth metal (for example, magnesium, calcium, strontium, barium etc.) also add for the hear resistance that improves cellulose esters as the nertralizer of catalyst sulfuric acid simultaneously.Simultaneously, can be as for the equivalent proportion of residue alkali metal or alkaline-earth metal and residual sulfuric acid referring to US patent application serial number No.08/151,037.

Preferred cellulose vinegar comprises organic acid esters (for example, containing the organic acid esters of 2-4 carbon atom) as cellulose acetate, cellulose propionate, cellulose butylate, cellulose acetate propionic ester, and cellulose acetate butyrate, wherein cellulose acetate is particularly preferred.The degree of acetylation of cellulose acetate is generally in about 43%-62% scope, and those have high biodegradability in conjunction with acetate in the 30-50% scope.Therefore, the degree of acetylation of cellulose acetate can be selected in the 30-62% scope.

The coated weight of cellulose esters can be in coating cellulose (A), based on the coating cellulose total amount, is no less than about 0.1% of gross weight.(for example, being about the 0.1-50% of weight), preferably be no less than about 1% (for example, being about the 1-30% of weight) of weight, be more preferably about 5% (5-15% that for example, is about weight) that is no less than weight.During practical application, coating cellulose can be about the 0.5-15% of weight, about 1-12% of preferred weight by the ratio of cellulose esters coating.Specifically, if the coating amount is less than 0.1% of weight, smoking quality and the ability of effectively removing harmful components in the tobacco will reduce, but when coating amount overweight 50% the time, biodegradability and capacity of decomposition will reduce.

Coating cellulose as the filtering material component of the present invention (A) can obtain by being coated with the last layer cellulose esters for fibrous or specific cellulose.Coating procedure is finished by following technology.By use (1) dipping, or (2) spray quinoline, and dry products therefrom (following solution-infusion process and the solution-spray drying method of referring to respectively); (3) plain and mixture cellulose ester solution joins technology (following finger mixing addition method) in the poor solvent of cellulose esters with fibrous or special fiber; Or the technology (following finger mixing-spray quinoline seasoning) of (4) spray said mixture makes fiber or particle surface enclose or be stained with cellulose ester solution.

The used solvent of cellulose ester solution can be selected in the optimum solvent of cellulose esters, and they comprise, for example, and organic solvent such as acetone, butanone, dioxanes, acetic acid etc.; Mixed solvent such as acetone-water mixture, carrene-alcohol mixture, acetate-aqueous mixtures, methylene chloride-methanol mixture etc.Preferred acetone is solvent for use.

Now explain above-mentioned each manufacture method in detail.

(1) solution-infusion process

This method comprises fibrous or special fiber is plain is immersed in the cellulose ester solution, and with the products therefrom drying to form the coating or the covering of cellulose esters.

The concentration of cellulose esters in cellulose ester solution generally is about the 0.01-30% of total solution weight, and preferably about 0.1-20% is more preferably about 0.1-10%.When the concentration overweight 30% the time, therefore the viscosity of solution will increase and cause processability (machinability) forfeiture.The plain ratio with respect to cellulose ester solution of fibrous or special fiber can be selected in a big way, generally the former: the latter is about 1: 10000 to 1: 1 (weight ratio), preferred about 1: 200-1: 20 (weight ratios).Dip time can suitably be selected according to concentration or other conditions of cellulose ester solution, for example, and several approximately seconds or more.(for example, about 3 seconds to 10 minutes, preferred 5 seconds to 3 minutes).

Cellulose fibre that floods in cellulose ester solution or particle will dry in air or heat drying, so that form coat at cellulose fibre or particle surface.

(2) solution-spray drying method

This method is to use cellulose ester solution that cellulose fibre or particle are sprayed, and with the products therefrom drying to form coat.

In this method, the concentration of cellulose esters in cellulose ester solution generally is about the 0.01-25% of weight.(for example, putting the 0.1-15% of weight approximately), the 0.5-10% of preferred weight (for example, accounting for the 0.1-7% of weight).The plain ratio with respect to cellulose ester solution of fibrous or special fiber can be selected in a big way, such as the former: the latter is 1: 100-1: 0.5 (weight ratio), preferred about 1: 20-1: 1 (weight ratio), and be more preferably about 1: 10-1: 2 (weight ratios).When using fibrous cellulose such as paper pulp, this fibrous cellulose of cracking in advance can guarantee the uniformity of cellulose ester solution spray, uses the cellulose esters can be by using the fiber that cellulose ester solution spray or particle dries or the heat drying acquisition to the coating cellulose of fiber or particle surface coating.

(3) mixture-addition method

This method is described to add the poor solvent of cellulose ester solution and stirs to form the method for coat in the mixture of cellulose fibre or particle and cellulose ester solution.

In this method, to be cellulose ester solution condense or precipitate formation at fiber or particle surface coat.In this course, when poor solvent is joined mixture, allow a shearing force effect on it, then can be suppressed to and stop cellulose esters excessive in surface attachment, and therefore can be efficiently and obtain the coating of fiber or particle surface uniformly.Shear force generally can be by using mixer thereon, homogenizer, centrifugal pump, agitator or analog acquisition.

The ratio of the cellulose esters that cellulose ester solution can actually contain, based on total solution weight, weight ratio is about 0.1-30%, and preferred weight ratio is 1-25% (for example, weight ratio is 1-10%).If used solution contains the weight ratio of cellulose esters greater than 30%, then the viscosity of solution increases, particularly when the ratio of cellulose fibre or particle was very big, the even dispersion or the mixing of fiber or particle were difficult to reach, and therefore caused degree of the being coated with effect of fiber or particle surface to reduce.

Cellulose fibre or the particle concentration in mixture, in the amount of the mixture is that the basis is with solid, account for about 0.01-80% weight of weight, preferred about 0.1-40 weight %, be more preferably 1-20 weight %, in fact, mixture can be made up of cellulose fibre or the particle of the about 0.1-10% of weight, preferably accounts for about 1-5% of weight.

Example as the cellulose esters poor solvent can be a water; Aromatic hydrocarbons such as benzene, toluene and dimethylbenzene; Aliphatic hydrocarbon such as hexane; Alicyclic such as cyclohexane; And lam-oil (kerosene).Preferred poor solvent comprises water.The consumption of poor solvent can be selected in a big way, and it is about 1-1000 times (weight ratio) of amount of the mixture, and preferably about 10-100 is (weight ratio) doubly.

(4) mixture-spray drying method

According to the method, coating can be passed through composite fibre shape or special fiber element and cellulose ester solution, and spray drying gained mixture obtains.

Illustrate, in this method, use spray dryer or analog that mixture is sprayed in the air-flow (for example high temperature gas flow) so that cellulose esters in fiber or particle surface coating.

The concentration of cellulose esters in cellulose solution is about 0.1-30% weight usually, and preferred weight is 1-25%.(for example, weight is about 1-10%).30% go up in limited time when cellulose esters concentration overweight, the viscosity of solution will increase, and therefore, the ratio of cellulose ester fiber or particle is very high in actual conditions, fiber or particle are difficult to be disperseed equably or mix, so that fiber or the effective coating of the very difficult acquisition of particle surface.Cellulose fibre or the particle ratio in mixture is, in solid, accounts for about 0.01-20% of mixture total weight amount, and preferred weight is about 0.1-10%, is more preferably weight and is about 0.5-5%.

At the aggregation phenomenon that the dry run floating coat cellulose of producing coating cellulose forms, thisly gather that cracker such as treater are cleaved to be fallen with being used.In addition, the coating amount of cellulose esters can contact with this surface of gathering by the solvent (for example, seldom measuring) that allows cellulose esters, so that partly remove or eliminate cellulose esters and control, and therefore can reduce the size of gathering.

By accident, as mentioned above, it is by with solution impregnation that contains hydrophobic polymer or spray paper that the open No.1944/1969 (JP-B-44-1944) of Japan Patent discloses a kind of tobacco filter, and gained paper is fixed to bar-shaped making.In this tobacco filter, owing to the adding of hydrophobic polymer makes cellulose fibre or analog adhesion or coated, therefore, this filter-tip wet decomposability has been lost widely.

Opposite with it, according to the present invention, filtering material is to prepare by using cellulose esters to component fibre or grain coating, be fixed to the shape of wanting (for example sheet) in advance.Therefore, filtering material of the present invention is to hold back high capacity of decomposition to be arranged when wet, and armaticity and palatability have all improved widely during its smoking.

As described, method of the present invention, fibrous or surface-coated that special fiber is plain cellulose esters, it is characterized in that more easily obtaining having the coated fiber of thin or good solidity or than the coating granule of small particle size so that coating cellulose has bigger surface area.

Now specifically describe cellulose derivative (B).

Cellulose derivative (B) is fibrous or given shape, and the esterification part of superficial layer wherein and the non-esterified part of core form by the esterification surface.Esterification fibrous or the plain derivative of special fiber partly is made up of cellulose esters.As this ester, can be illustrational ester when explaining coating cellulose (A) as mentioned above.

The preferred organic acid esters (for example, containing the organic acid esters of 2-4 carbon atom) of esterification part forms or forms, preferred especially acetate.

This average substitution degree fibrous or the plain derivative of special fiber should be not more than 1.5 (for example about 0.01-1.5), preferably about 0.02-1.2, and more preferably 0.05-0.5.If average substitution degree surpasses 1.5, esterification will be excessive, and make the core (inside) of fiber or particle also esterified, and will therefore cause reducing of biodegradability.When average substitution degree less than 0.01 the time, feature such as the smoking quality required as filter tip will descend.

Simultaneously, here be used for explaining that cellulose derivative (B) " average substitution degree " is meant the average degree that cellulose fibre or particle replace, as a whole, esterification is uneven, here indication or notion be different from and use described solubilising esterification so that homogeneous reaction or replace " substitution value " notion used when making cellulose ester fiber or particle.

The fibre diameter of fibrous cellulose derivative (B) and fibre length can suitably be selected in a big way under the condition that does not influence as the required feature of filter tip, but fibrous cellulose derivative practical application short fiber.The fibrous cellulose derivative generally has fibre diameter and (for example is about 0.01-100 μ m, about 1-50 μ m) and fibre length (for example be about 50 μ m-10mm, about 0.1-10mm, preferably about 0.5-4mm) use fibre diameter and the cellulose derivative of fibre length in above-mentioned scope can make filtering material have the pressing mold processability that high strength is become reconciled.

There is no particular limitation for the cross sectional shape of fibrous cellulose derivative, can be circular, oval or other Any shape.Therefore, fibrous cellulose can be fixed to the cross section (for example, Y-, X-, R-or T-shape) or hollow.Fibrous cellulose can be curled if necessary, but generally use non-crimping shape.

The present invention preferably uses fibrous cellulose, but given shape (specially referring to Powdered) cellulose also can use.The big I of specific cellulose grain is selected in a big way under the condition that pressing mold processability (formability) and disintegration ability are had no adverse effect.Therefore, specific cellulosic mean particle size is about 0.1-600 μ m, preferably 10-500 μ m and more preferably from about 20-250 μ.If mean particle size is less than 0.1 μ m, then this particle will be removed from material, and when particle greater than prescribing a time limit 600 μ m on, then the material specific area that will lose surface flatness and material will reduce.

Fibrous or specific cellulose derivative (B) is in the surface of holding fiber or particle (superficial layer) esterification, and fiber or particle also contain a non-esterified zone at the center of fiber or particle.In this fibrous or plain derivative of special fiber, participate in or fiber or the particle surface relevant with smoke filtration esterified.Therefore, the filtering characteristic of this derivative is the same with the traditional filtering mouth of being made up of the acetic ester fiber tow good with the ability of effectively removing the tobacco harmful constituent as the smoking quality.In addition,, and forms, so this cellulose derivative has and wood pulp or regenerated celulose fibre or its analog high biodegradability equally by non-esterified natural or regenerated cellulose because that the core of fiber or particle does not have is esterified.Therefore, cellulose derivative of the present invention (B), its function is born respectively by superficial layer and core, it is characterized in that having both sides' function, the promptly good smoking quality and the high biodegradability coordinating and unifying.

The esterification of fibrous or specific cellulose derivative distributes and can be proved conclusively or confirm, by for example, uses direct dyes (directly color) or disperse dyes to fibrous or specific cellulose derivative dyeing, and observes the cross section of fiber or particle.That is, esterification part dyeable with disperse dye, and can not be by direct dyeing.On the contrary, no esterification and unsubstituted part can be by direct dyeings and can not be by disperse dyeings.Fibrous or specific cellulose derivative (B) is by and being formed by the core of direct dyeing by the fiber of disperse dyeing or particle surface part (superficial layer).

The plain derivative of fibrous or special fiber can derive from natural or regenerated cellulose.As the raw material of cellulose fibre or particle, can be illustrational those natural or regenerated celluloses when explaining coating cellulose (A).These natural or regenerated celluloses can use separately or be used in combination.

Fibrous or specific cellulose derivative (B) can prepare by the following method, for example, (5) in the poor solvent of cellulose esters as hexane and toluene, in the presence of catalyst (following finger catalyst method), use the organic acid acid anhydrides, organic acid halide or analog are handled natural or regenerated celulose fibre or particle, and (6) comprise and use organic acid, with organic acid acid anhydrides or halide, or similar techniques is handled the method for natural or regenerated celulose fibre or particle.

Catalyst as catalyst method (5) can use alkali, as pyridine; With the alkali metal salt such as the sodium acetate of organic carboxyl acid, potassium acetate.In traditional handicraft, acid catalyst such as sulfuric acid and perchloric acid are used in cellulose fibre or particle esterification.But,, be difficult to obtain at cellulose fibre or particle surface by fatization and the core keeps non-esterified state because this catalyst has very strong penetration power or penetration to cellulose fibre or particle.

In method (6), processing can be carried out in the presence of catalyst, but does not preferably use the processing of catalyst.Simultaneously, the poor solvent of cellulose esters can be used on when explaining coating cellulose (A) illustrational those.

Handle in liquid phase organic acid and organic acid acid anhydrides or liquid phase organic acid and organic acid halide according to method (6) fiber or particle.Even also can be in the presence of catalyst-free, and can reduce the further esterification of fiber or granule interior (core) with cellulose fibre or particle surface esterification.Therefore, the fibrous or plain derivative of special fiber of the present invention can obtain easily or promptly.In addition, need not use aromatic solvent (for example hexane, toluene etc.) in the method, therefore, not need solvent processing procedure and similar operations, and therefore improve condition of work.Moreover used organic acid and organic acid acid anhydrides or halide itself are highly biodegradable in the method, and therefore, though they stay fibrous or the plain derivative of special fiber in, the biology that also can not reduce material reduces ability.

The organic acid example comprises aliphatic saturated carboxylic acid such as acetate, propionic acid and the butyric acid that contains 2-4 carbon atom.These organic acids can use separately or be used in combination.Preferred organic acid comprises, and is representational as acetate.

As organic acid anhydride or organic acid halide, can select organic acid acid anhydrides or its halide such as chloride for use, bromide and iodide etc.If required ester is a mixed acid ester, can be suitably in conjunction with application of anhydride and/or sour halide.

As long as guarantee the surperficial esterified of fibrous or specific cellulose derivative under the not esterified institute in the core situation of fiber or particle, can be in a big way the choice reaction condition.Therefore, reaction temperature is generally about 40-120 ℃, and preferably about 60-100 ℃, the reaction time generally is about 10 minutes to 10 hours and preferred 30 minutes to 3 hours.

The organic acid consumption can be selected in a big way, for example is about 5-500 times (weight ratio) of raw material cellulose fibre or particle weight, and preferably about 20-200 is (weight ratio) doubly.The organic acid acid anhydrides or/halid ratio can select in a big way, for example with respect to the 5-500 of raw material cellulose fibre or particle weight doubly (weight ratio), and preferred 20-200 doubly (for example 20-100 doubly) (weight ratio).

According to aforesaid method, the surface of cellulose fibre or particle can be esterified, but the core of fiber or particle still keeps not esterified natural and regenerated cellulose.Therefore, can under the condition that does not reduce smoking quality (armaticity, the sense of taste, palatability etc.), obtain outstanding biodegradability as mentioned above.In addition, can more easily obtain to have the fine fibre of less fibre diameter or have granule, and therefore make filtering material have bigger specific area and the efficient ability of removing the tobacco harmful constituent by esterify cellobiose shape or specific raw material than minor diameter.

Coating cellulose of the present invention (A) and cellulose derivative (B) have high biodegradability, and therefore can be used as production Biodegradable material such as Biodegradable fibers, paper and filter tip.

Filtering material of the present invention is made up of above-mentioned fiber or particle, be that fiber or particle have a core and surround the superficial layer of core, wherein superficial layer is made up of cellulose esters and core is made up of nonesterified cellulose, for example, and coating cellulose (A) and/or cellulose derivative (B).These component materials can use separately or be used in combination, also can application of coatings cellulose (A) and the bond of cellulose derivative (B).

Coating cellulose (A), cellulose derivative (B), and the filtering material of the present invention that contains these combined materials has high biodegradability, and can show, for example, according to ASTM (U.S. test and materialogy meeting) (D5209-91, with the amount that discharges carbon dioxide as indication, the degradation rate of measuring 4-week is not less than 20% of weight, (for example, 30%-100% weight) preferably is not less than 40% of weight, (for example, being about 50-100 weight %).In the test of biological degradability, the activated sludge that the municipal sewage plant uses can be used as activated sludge.Degradation rate fibrous or the plain derivative of special fiber can be converted into the percentage calculation of the carbon number of carbon dioxide release with respect to the possible the total number of carbon atoms before not degrading by mensuration.These materials and component material have high biodegradability equally under enzyme such as cellulase effect.

There is no particular limitation for the form of material, for example, can be fiber, suede class (fur or fine hair), woven fabric, adhesive-bonded fabric, tow (fibre bundle) or sheet.Preferable material is to have non-woven cancellated flaky material.Simultaneously, used here " network structure " is meant the fabric construction of fiber interweaving or entanglement.For these reasons, sheet shape filtering material has high dried paper intensity and is running under the situation of being got wet as rainwater or analog and can decompose automatically rapidly.

Filtering material can be manufactured, for example, (1) with the filtering material of coating cellulose (A) and/or cellulose derivative (B) or be fixed to net slice and obtain filtering material, make it complete method of coming moulding by packing, (2) wet into net to make the method for sheet filtering material by making the slurry that contains coating cellulose and/or cellulose derivative in the sheet pattern.

Filtering material of the present invention in containing above-mentioned scope fiber or particle also can contain other do not have bad influence to material characteristics component.These components can be that fiber or particle use with component material, for example, and as the illustrational natural or regenerated celulose fibre of cellulosic fibre raw material; Natural fiber such as wool; Synthetic fibers such as cellulose ester fiber, polyolefine fiber (for example, polyethylene fibre or polypropylene fibre), polyester fiber (for example, dacron fibre), vinal, Fypro and analog thereof.These components also can particle form be used, and can separately or be used in combination.Natural or regenerated fiber, particularly wood pulp are because its high biodegradability uses highly beneficial.

Only otherwise reduce feature such as the smoking quality and the biodegradability of filtering material, the ratio of fiber or particle and other components can be selected in a big way, they are, for example, the former/latter's ratio is about 99/1-20/80 (weight ratio), preferred about 99/1-40/60 (weight ratio), more preferably 98/2-60/40 (weight ratio).The practical application ratio is 95/5-80/20 (weight ratio).

Under the condition that feature such as biological degradability to filtering material do not have bad influence, fiber or particle shared ratio in filtering material can be selected in a big way, they are, for example be not less than the filtering material gross weight 30% (for example, the 40-100% that is about weight), preferably is not less than 50% of weight, (for example 55-100% of weight), and more preferably be not less than 60% (for example, the 65-100% of gross weight) of gross weight.

Fiber or particle and filtering material are only otherwise the feature that influences them can contain multiple additives.The example of these additives comprises sizing agent, pulverizes good inorganic material powder and comprises kaolin, talcum, diatomite, titanium dioxide, aluminium oxide, quartz, calcium carbonate and barium sulfate; Stabilizing agent such as heat stabilizer comprise alkali salt (calcium, magnesium etc.), antioxidant and ultra-violet absorber; Colouring agent and volume increase agent.In addition, (for example, having specific area is 100-300m to mix cellulose as microfibrillated with paper-intensity reinforcing agent ²The microfibrillated cellulose of/g, fibre diameter are no more than 2 μ m, preferably are no more than 1 μ m and fibre length and are about 50-1000 μ m), can improve dried paper intensity.The environment degradable of filtering material can mix by the material with above-mentioned high biological degradability or disintegrative and improves.Add biodegradation accelerator such as citric acid, tartaric acid, the titanium dioxide that maleic acid and analog thereof and/or light degradation accelerator such as anatase form.

As long as under the situation of the feature that does not influence material such as disintegrative and biodegradability, filtering material also can contain plasticizer such as glyceryl triacetate or triethylene glycol diacetate, but because emphasize wet decomposability, preferably filtering material does not contain these plasticizer and therefore can improve filter-tip degradability or decomposability.

Filtering material can contain adhesive in case of necessity.In this case, preferably use water-soluble binder to improve wet decomposability.As water-soluble binder, the example that can have as, natural glue such as starch, modified starch, soluble starch, glucan gum arabic, mosanom, protein (for example, casein, gelatin etc.); Cellulose derivative such as carboxymethyl cellulose, hydroxyethylcellulose; Ethyl cellulose and and analog; And synthetic resin adhesive such as polyvinyl alcohol, poly--the N-vinylpyrrolidone, water soluble propene's resin etc.These adhesives can independences or are used in combination.

When water-soluble binder is used with the form of the aqueous solution or dispersion, can cause the forfeiture of filter stick intensity and solidity according to the consumption of aqueous solvent, even not only when packing filtering material with wrapping paper, and intensity also greatly reduces when blocking rod to filter length.Particularly when when using dipping method as component fibers or particle and use the aqueous solution of water-soluble binder, the intensity and the solidity of material have significantly reduced.Therefore, when water-soluble binder is used with the form of the aqueous solution or dispersion liquid, preferably reduce the amount that in fiber or particle, adds entry.On the other hand, hotmelt (water-soluble hot melt adhesive) is the adhesive for solvent-free use that plays adhesive effect in fusing one process of setting, therefore and there is not an above-mentioned trouble, such water-soluble binder (water-soluble hot melt adhesive) comprises the polymer that those show hot melt adhesive, the polyvinyl alcohol that has as representative, poly-alkylene oxygen, polyamide, polyester and acrylic polymers.

Tobacco filtering material of the present invention has aforesaid high biodegradability, and in the manufacturing of tobacco filter (cigarette filter rod) of great use.Above-mentioned tobacco filter can be by traditional manufacture process manufacturing, for example (a) comprises and makes filter stick form mould with fibrous, Powdered or similar filtering material is as filler, form the process of filtering plug, or (b) comprise use plug coiling machine reel spirally or folding of sheet material to form the process of filtering plug.According to process (b), with flaky material by reel or folding typing after dry again, or, selectively, before type-approval process earlier with the flaky material drying.

The filtering material of preferred use folding crape or embossing does not have channel but a level and smooth and uniform passage when aspirating by filtering plug with the assurance tobacco.By rolling over crape or the embossing filtering material is wrapped, can obtain a filtering plug that uniform cross-section and attracting surface are arranged.The folding crape can form wrinkle by a pair of folding crape cylinder with forward direction rotation of multiple-grooved by making flaky material, and along direction of advance slight slight crack is arranged.Embossing be by be make flaky material by one by the clathrate of protruding and/or concave portion or arbitrarily the cylinder that forms of hollow relief or flaky material is pressed on the cylinder with these hollow reliefs carry out.

The spacing of folding crape groove and the spacing of the degree of depth and embossing mould and the degree of depth can be about 0.3-5mm (for example about 0.5-5mm) and the degree of depth is about selection in 0.1-2mm (for example about 0.1-1mm) scope in spacing.

The feature of sheet filtering material such as pressure drop (anti-suction) and trap and all controllable advantage of elimination factor.In addition, by wrinkle or embossing, make filter tip when tobacco is aspirated, have enough gas permeabilities (panting property).

Illustrate, can make filter tip when tobacco is aspirated, satisfied gas permeability be arranged, for example have pressure drop (anti-suction) and be about 200-600mmWG (water column) and preferably about 300-500mmWG (mmH by folding crape or embossing ₂O or mmAq).

In above-mentioned plug forming machine, the flaky material of folding crape or embossing is put into a funnel, become a cylinder with packing thin paper or paper bag, paste and be cut into certain-length filter made plug.In packaging process, the virtual package of the sheet shape filtering material of doubling crape is to pack with its wrinkle or the vertical direction of microgroove length direction.

In making filtering plug, paste at the wrapping paper edge and the stickup between cylindricality filtering material and wrapping paper is necessary, the preferred water soluble adhesive as glue so that wet disintegration ability do not reduce.Applicable this water-soluble binder comprises that for example aforesaid, these water-soluble binders can separately or be used in combination.

Aforesaid tobacco filter has kept the fragrant post (sense of taste) and the palatability of gratifying smoking.That is, its component fibre or particle, for example, coating cellulose (A) and/or cellulose derivative (B) can provide outstanding smoking quality and high biological degradability, and actual wet decomposability.Therefore, even filter tip is discarded in outdoors, it also can decompose rapidly after having contacted rainwater or analog, has therefore reduced the danger of polluting.

The biodegradation of having a mind to of tobacco filter can be carried out under the outdoor exposure condition, is 0-50 ℃ in temperature for example, and preferred 10-40 ℃, relative humidity is about 30-90%.Be the biodegradation of accelerated filtration mouth, it is of great use that transient nozzles is placed the organic acid soil or the water that contain the cellulosic microorganism of adaptation and constitute cellulose esters.Use contains these activation of microorganism mud can improve filter-tip biodegradability.

Fiber that the superficial layer of the encirclement core that core and cellulose esters form constitutes or particle form because tobacco filtering material of the present invention and tobacco filter are made up of non-esterified cellulose, so can not reduce the smoking quality and have biodegradability, and therefore alleviate the environmental pollution burden.In addition, this filtering material and filter tip can also provide high filter efficiency.Moreover when filtering material and filter tip composition, for example, coating cellulose (A) also can obtain the high humidity decomposability simultaneously, and although they have high dried paper intensity, when their were got wet, they can very fast automatic degraded.Harmful components when in addition, they have also guaranteed effective removal smoking in the tobacco also have enough anti-suction (pressure drop) abilities and outstanding pressing mold processability and biodegradability.

According to production process of the present invention, the tobacco filtering material with above-mentioned praiseworthy characteristics can be produced.

The specific embodiment

Following embodiment is for the present invention being described in further detail, should not be construed as limiting the scope of the invention.

Embodiment

Divide (collapsing) separating property, solidity, weight, the coating amount, average substitution degree, viscosity one average degree of polymerization and anti-suction force are calculated in embodiment and reference examples as follows.

Water decomposition rate (%): about 0.2g sample of accurate weighing is put into the 1 liter of flask (its overall diameter is 110mm, and high is 150mm) that contains 500ml water and made the vortex core height with the magnetic stirrer stirring is 1/2 of liquid level.After 30 minutes, slurry is filtered and measures the dry weight of filter cake by 5 order metallic screens.

Then, be used for estimating that the water decomposition (%) of wet decomposability is by following equation calculating.

Water decomposition rate (%)=100 * [1-(B/A)] be the weight of A representative sample (g) wherein, B represent filter cake in heavy (g).

Canadian standard solidity (ml): the P-8121 of Japanese Industrial Standards (JIS)

Weight (g/m ²): JIS-P-8121

Coating amount (weight %): accurate weighing raw materials fiber or powder, use the acetate fiber element coating then.The gained coating cellulose is in 105 ℃ of dryings 2 hours and weighing.The coating amount of cellulose acetate is by measuring by following equation calculated weight increment.

Coating amount (weight %)=100 * [(D-C)/D] wherein C represented the weight (g) of raw material cellulose (wood pulp), and D represents cellulosic weight (g) after the coating.

Average substitution degree: add acetone (120ml) and dimethyl sulfoxide (DMSO) (30ml) makes it swelling in the 1.9g sample, to wherein adding the 30ml 1N-NaOH aqueous solution, saponification is 2 hours under stirring at room then.After reaction is finished, in the gained mixture, add hot water 100ml and stirred 5 minutes, in mixture, add pure water 25ml again.Like this, average substitution degree is to use 1N-H ₂SO ₄It is that indicator is measured with phenolphthalein that aqueous solution back titration consumes alkali.

Viscosity one average degree of polymerization: drying sample (0.5000g) is accurately weighed (C) and put into the 100ml recorder jar.In sample, add the about 70ml of acetone and make it to become solution.Solution temperature is transferred to 25 ℃ and continue to add acetone and make solution reach 100ml.In Ostwald viscosimeter, add 10ml gained solution.Measure solution and solvent (acetone) Drain time in the time of 25 ℃ respectively, be accurate to 0.01 second, and viscosity one average degree of polymerization (DP) calculates by following formula.

[η]-(ηsp/C)/(l1k×ηsp)

ηsp＝t/t ₀-1

k-0.366

DP＝169.93×·[η] ^1.623

Wherein t represents the Drain time (second) of cellulose ester solution, t ₀Represent the Drain time (second) of solvent (acetone), the weight of C representative sample (cellulose esters).

Anti-suction force: with filter tip and the parallel placement of U-type pipe water column and connect a last vavuum pump, the water column changing value was represented (Water Gauge, H when anti-suction force was measured air by filter tip with 17.5ml/ second ₂O).

Biological degradability can be measured by following two kinds of methods:

(1) active puddling: according to ASTMD 5209-91, the active mud that cultivate the municipal sewage plant can be used as active mud.As for laboratory sample, each test specimen 2g in liquid nitrogen freezing 3 minutes and added in the coffee powder 3 minutes in advance.Base-material in liquid nitrogen freezing 1 minute and obtained laboratory sample (100 orders sieve) in 3 minutes with concussion pulverizer pulverizing.

Use laboratory sample concentration to be 30ppm (9mg feeds intake) as 100ppm (30mg feeds intake) and described active concentration of hydraulic mixture, test carried out for 4 weeks under 25 ± 1 ℃ of conditions, the free carbon atomicity that degradation rate transforms by the amount of carbon dioxide that discharges is with respect to the percentage calculation of total carbon atom number in the test specimen.

(2) enzyme edman degradation Edman: the degradability (decomposability) that this method is measured is caused by enzyme.Promptly, the 20ml buffer solution (PH4.8) that in the 0.1g sample, adds the cellulase [Cellcrast 1.5N (trade name), by Novo Nordisk Bioindustries, Ltd. makes] that contains 288CUN, and with the gained mixture under 45 ℃, stir and reacted in 7 hours.After reacting completely, with G4-glass filter filter reaction mixture, with the residue drying, assaying reaction is the back example weight fully.The surplus ratio of sample calculates with the following formula equation.

Surplus ratio (%)=[X/0.1] * 100

Wherein the weight of back sample is reacted in the X representative.

The smoking quality test is carried out as follows: sample is fixed to filtering plug in advance, and with the cigarette (trade name: Wakaba is made by Japan Tobacco Inc) that market is bought, filter tip is got rid of, and connects the sample filtering plug.And use this sample, use 5 custom smokers to carry out the test of smoking quality such as armaticity (sense of taste) and palatability by following standard as target.The rank of sample armaticity and palatability is the mean value of 5 people's measured values.

Bioassay standard:

3 grades of armaticity and palatability: the cigarette of inhaling by sample do not have heat (acid) sense of taste (armaticity) and cigarette very good to eat.

2 grades of armaticity and palatability: cigarette sucks up the no pungent sense of taste but is not good to eat.

1 grade fragrant grade and palatability: cigarette has sucked up acid.Embodiment 1

It is that the bleached softwood sulphate pulp of 270ml is dipped into the cellulose acetate that contains 0.15% weight (degree of acetylation is 55.5% that 10g is had Canadian standard consolidation value; average substitution degree is 2.45; residue calcium and residual sulfuric acid mol ratio are 1.2; average degree of polymerization is 370) the 500ml acetone soln in 15 seconds; and stir; wherein slurry is to use water-splitting, replaces with acetone, stirs acquisition in 15 seconds.Impregnated slurry taken out at air drying obtained in surface-coated the coated fiber of cellulose acetate.In coated fiber, the coating amount of cellulose acetate accounts for 5.0% of total coated fiber weight.The gained coated fiber is dispersed in 50 premium on currency, and uses the gained slurry, utilize the conventional wet knitting skill to be woven into net.This net dehydration and drying are obtained the heavy 30g/m of a tablet ²The water decomposition rate of this tablet is 65.9%.As for biological degradability, the 4-week degradation rate that this tablet is measured by active puddling is 63%, and the surplus ratio that connects enzyme edman degradation Edman mensuration is 72.2%.Embodiment 2

10g is passed through to use water-splitting; place acetone again; again by removing by filter the bleached softwood grafting pulp that Canadian standard consolidation value is 270ml that has of solvent gained; under agitation; (degree of acetylation is 55.5% to join the cellulose acetate that contains 3% weight; average substitution degree is 2.45, and residue calcium and residual sulfuric acid mol ratio are 1.2, and average degree of polymerization is 370) the 400ml acetone soln in.The gained mixture is placed-water-bath is fully stirred with agitator, and therefore, cellulose acetate is assembled or solidified.Gains are at the air drying coated fiber of cellulose acetate that obtained surface-coated.Use the gained fiber, use conventional art and press embodiment 1 and operate knitmesh equally, and dehydrate that to obtain weight be 34.1g/m ²Tablet.Result as measuring disintegrative and biological degradability proves that this tablet water decomposition is 63.2%, and the degradation rate that uses active puddling is 63%, and using the surplus ratio of enzyme edman degradation Edman is 71.5%.Embodiment 3:

Repeat the operating process of embodiment 2, just use is contained the cellulose acetate acetone soln coating of 5.0% weight, the coating amount that obtains cellulose acetate is the coated fiber of 9.7% weight.Use the coated fiber that obtains like this, obtaining weight by embodiment 1 operation is 34.6g/m ²Tablet.Measure the decomposability and the biodegradability of this tablet, its result shows that the water-destructible property of tablet is 60.2%, and the degradation rate of measuring by active puddling is 59%, and the surplus ratio of measuring by the enzyme edman degradation Edman is 72.1%.Embodiment 4

(degree of acetylation is 55.5% to join the cellulose acetate that contains 5.0% weight with 30g cellulose powder (cork sulphate pulp 60 orders of cracking and bleaching sieve); average substitution degree is 2.45; the mol ratio of residue calcium and residual sulfuric acid is 1.2; average degree of polymerization is 370) 1 liter of acetone soln in, use the agitator dispersion that stirs.Use and have the nozzle of diameter as 1mm, with the speed of 1mm per second, the gained mixture is clamp-oned water-bath, described water-bath has blade (paddle) with 10, the rotation of the speed of 000rpm is stirred, and has therefore made coating and be 9.76% the coated fiber of cellulose acetate on surface-coated of weight.Use this coated fiber such as embodiment 1 operation, obtaining weight is 25.0g/m ²Tablet.The water-destructible property of this tablet is 58.6%, and as for biological degradability, the 4-week degradation rate that this tablet is measured by active puddling is 60%, and recording surplus ratio with the enzyme edman degradation Edman is 76.4%.Embodiment 5

(degree of acetylation is 55.5% to join the cellulose acetate that contains 1.0% weight with 10g powdery cellulose (sieve get from bleached softwood sulphate pulp 330 orders); average substitution degree is 2.45; the mol ratio of residue calcium and residual sulfuric acid is 1.2; average degree of polymerization is 370) 1 liter of acetone soln in, use agitator to disperse to obtain a mixture equably.This mixture spray is also dry under 100 ℃ of air-flows with spray dryer, obtains the cellulose powder that the surface is applied by cellulose acetate.Cellulose acetate proportion in coated powder is about 10.2% weight.Use the coated powder of gained, adopt identical wet knitting skill knitmesh among the embodiment 1, it is 25.0g/m that this net dehydration and drying are obtained weight ²Tablet.Measure the resolution ratio and the biological degradation rate of this tablet, the gained result, the water decomposition rate of tablet is 61.2%, using active puddling to record degradation rate is 60%, and to use the enzyme edman degradation Edman to record surplus ratio be 73.0%.Embodiment 6

10g replaces the bleached softwood sulphate pulp that also fully wrinkles but do not tangle with acetone again through water-splitting; to this pulp surface of not tangling spray 30g acetone soln; it is that (degree of acetylation is 55.5% for 1.0% cellulose acetate that this solution contains weight; average substitution degree is 2.45; the mol ratio of residue calcium and residual sulfuric acid is 1.2; average degree of polymerization is 370), and, obtain the coated fiber that fiber surface is applied by cellulose acetate at air drying.Coated weight accounts for 1.8% of total coated fiber weight.Use this coated fiber, press embodiment 1 and operate equally, obtain a net, with this net dehydration and dry, obtaining weight is 28.4g/m ²Tablet.Measure the resolution ratio and the biodegradability of this tablet, the water decomposition rate of this tablet is 64.8%, and the degradation rate that uses active puddling to measure is 66%, and using the surplus ratio of enzyme edman degradation Edman is 70.1%.Embodiment 7

Pressing embodiment 6 operation, is that obtaining cellulose acetate coating amount is the coated fiber of 5.7% weight ratio 3.0% the cellulose acetate except acetone soln contains weight.Use this coated fiber by embodiment 1 operation, obtaining weight is 29.0g/m ²Tablet.Measure the resolution ratio and the biological degradation rate of this tablet, the water decomposition rate of this tablet is 62.2% as a result, and the degradation rate that uses active puddling to measure is 65%, and the surplus ratio that uses the enzyme edman degradation Edman to measure is 71.6%.Embodiment 8

Repeating embodiment 6 operations, is 5.0% cellulose acetate except acetone soln contains weight, obtains coated fiber (the coating amount of cellulose acetate is 9.4% weight).Use this coated fiber, press embodiment 1 and operate equally, obtaining weight is 28.6g/m ²Tablet.The water decomposition of this tablet, degradation rate that records with active puddling and the surplus ratio of measuring with the enzyme edman degradation Edman are respectively 56.1%, 61% and 73.5%.Comparative Examples 1

Use the bleached softwood sulphate pulp identical with embodiment 1, but without other, press the knitmesh of conventional wet weaving method, and will net dehydration, it is 29.5g/m that drying obtains weight ²Tablet, as the resolution ratio of this tablet and the measurement result of biological degradation rate, the water decomposition rate that this tablet demonstrates is 69.7%, the degradation rate that uses active puddling to measure is 73%, using the surplus ratio of enzyme edman degradation Edman is 54.3%.Comparative Examples 2

Mensuration has the cellulose acetate short fiber of the folding crape in Y-type cross section, and (consolidation was 3 dawn; fibre length is 5mm; degree of acetylation is 55.5%; average substitution degree is 2.45; the mol ratio of residue calcium and residual sulfuric acid is 1.2, and average degree of polymerization is 370), as a result of; the degradation rate that this fiber-reactive puddling records is 6%, and the surplus ratio of measuring with the enzyme edman degradation Edman is 96.8%.Embodiment 9

The width that will be obtained by embodiment 1 is that the sheet filtering material of 28cm is knit crape with beating crape cylinder (surface temperature is 150 ℃, and separation is 2.0mm, and groove depth is 0.7mm) with the speed of 100m/min.Material demonstrates good machinability.Beat the speed that the filtering material of crape can 250m/min, do not add under the condition of plasticizer, make filtering plug.This filtering plug is long to be 108mm, and girth is 23.5mm, and weight is the 1.05g/ plug.Embodiment 10-16

Filtering plug is made in operation by embodiment 9, but uses the sheet filtering material of embodiment 2-8 respectively.Comparative Examples 3

Repeat the process of embodiment 9, but the sheet filtering material that uses Comparative Examples 2 to obtain is made filtering plug.Comparative Examples 4

Filtering plug (108mm is long, 23.5mm girth, heavy 1.10g/ plug) obtains as above-mentioned same method, except using as the cellulose acetate short fiber bundle in the comparison example, also uses glyceryl triacetate as plasticizer.

Measure the resolution ratio and the smoking quality of embodiment 9-16 and Comparative Examples 3,4 filtering plugs respectively, the result is as shown in the table.

Table

	Wet disintegrative	Armaticity and palatability rank
	Wet disintegrative	Armaticity and palatability rank	Embodiment 9 embodiment 10 embodiment 11 embodiment 12 embodiment 13 embodiment 14 embodiment 15 embodiment 16 Comparative Examples 3 Comparative Examples 4	67.6 65.6 61.8 60.2 62.8 66.4 63.5 57.7 71.8 4.0	2.6 2.8 2.4 2.2 2.6 2.8 2.6 2.4 1.2 2.8

From last table result as can be seen, the filter tip that is made by embodiment 9-16 has water decomposition rate preferably than the filter tip of Comparative Examples 4, and has compared smoking quality preferably with the filter tip of Comparative Examples 3, and its smoking quality is the same good with Comparative Examples 4.Embodiment 17

10g cork sulfonation slurry (alpha-cellulose content is 94%) was flooded 1 hour in 1000ml water, and be 5 times of slurry with de-watering of slurries to the water content of this dipping, gains replace with 100ml acetic acid.In addition, in said mixture, add 600ml acetic acid and 600ml aceticanhydride again.80 ℃ of reactions of oil bath are 1 hour in nitrogen stream.Reactant mixture is poured in the 3000ml water, and therefore, excessive aceticanhydride will decompose.The gained mixture is filtered, wash with water and dry to obtain having average substitution degree be 0.15 fibrous cellulose derivative (the long 4mm of fiber, fibre diameter 20 μ m).The biological degradability that this cellulose derivative is measured with active puddling is 61%.With fibrous cellulose derivative disperse dyeing (decompose Huang 3, make), and use the microscopic examination fibre section by Aldrich Chemical Company Inc..As a result of, have only the cylindrical zone (superficial layer) of fiber to be caught color, and therefore determine to have only the surface of fiber to be acetylation.Comparative Examples 5

Measure on the market average substitution degree in the tobacco filter and be the biological degradation rate of 2.4 cellulose acetate ester fiber (consolidation was 3 dawn, Y-type cross section).That as a result, uses that active puddling measures is degraded to 2%.Embodiment 18

To be packaged as interior diameter with wrapping paper by the fibrous cellulose derivative that embodiment 17 obtains is that 7.9mm and length are the filter tip of 17mm, and the pressure drop of bearing the 50mm water column of this tobacco filtering plug.Measure this filter-tip smoking quality according to the smoking quality test, its result, armaticity and palatability rank are 2.8.Embodiment 19

By weight, 90 parts of fibrous cellulose derivative and 10 parts of bleached softwood sulphate pulps that obtain from embodiment 17 are separated into a uniform sizing material 10000 weight parts waters, it is 35g/m that slurry obtains weight with porous plate dehydration and drying ²Tablet, this tablet is fixed to ripple type, and with wrapping paper this corrugated plate is packaged as and can bears the pressure drop of 50mm water column, having interior diameter is that 7.9mm and length are the filter tip of 17mm.This filtering plug is carried out the smoking quality test, its result, this filter-tip armaticity and palatability rank are 2.6.Comparative Examples 6

As embodiment 19 similar approach, use the bleached softwood sulphate pulp and, make filter tip (interior diameter is 7.9mm, and length is 17mm, and anti-suction force is 50mmWG) without other materials.Use smoking quality test method to measure its smoking quality, its result, this filter-tip armaticity and palatability rank are 1.2.

Claims

1. the filtering material that grows tobacco, this tobacco filtering material is made up of the fiber or the particle that have core and surround the superficial layer of core, and wherein superficial layer is made up of cellulose esters and core is made up of non-esterified cellulose.

2. the described tobacco filtering material of claim 1, wherein fiber or particle are:

(A) by coating cellulose fibrous or that special fiber is plain and cellulose esters is formed, wherein said surface fibrous or that special fiber is plain is applied by described cellulose esters, or

(B) the fibrous or plain derivative of special fiber of deriving and by native cellulose or regenerated celulose fibre or particle, wherein the non-esterified part of the esterification of superficial layer part and core forms by esterify cellobiose or particle surface, and described cellulose derivative average substitution degree as a whole is no more than 1.5.

3. the described tobacco filtering material of claim 1, wherein cellulose is the organic acid esters that contains 2-4 carbon atom.

4. the described tobacco filtering material of claim 1, wherein cellulose esters is a cellulose acetate.

5. the described tobacco filtering material of claim 1, wherein non-esterified cellulose is a wood pulp.

6. the described tobacco filtering material of claim 2, wherein in coating cellulose (A), the coated weight of described cellulose esters is the 0.1-50% weight of coating cellulose (A) gross weight.

7. the described tobacco filtering material of claim 2, wherein coating cellulose (A) is made up of wood pulp and cellulose acetate, the surface of described wood pulp is applied by cellulose esters, the average substitution degree of described cellulose esters is 1-3, and the coating amount of cellulose esters is the 0.1-50% weight of described coating cellulose (A) total amount.

8. the described tobacco filtering material of claim 2, wherein said ensemble average substitution value fibrous or the plain derivative of special fiber (B) is 0.02-1.2.

9. the described tobacco filtering material of claim 2, wherein said coating cellulose (A) or described cellulose derivative (B) are biodegradable.

10. the described tobacco filtering material of claim 9, wherein said coating cellulose (A) or described cellulose derivative (B) according to U.S.'s test and materialogy can D 5209-91 with the burst size of carbon dioxide serve as indication measure 4 week degradation rate be the 20-100% weight of gross weight.

11. the described tobacco filtering material of claim 2, wherein said coating cellulose (A) or the described fibrous or plain derivative of special fiber (B) are that to have fibre diameter be that 0.01-100 μ m and fibre length are the fiber of 50 μ m-10mm.

12. the described tobacco filtering material of claim 2, the 30-100% weight that wherein contained coating cellulose (A) or ratio fibrous or the plain derivative of special fiber (B) are the filtering material total amount.

13. the described tobacco filtering material of claim 1 is sheet shape.

14. the described tobacco filtering material of claim 13 is by wrinkle or embossing.

15. the described tobacco filtering material of claim 1 is to have cancellated shape, and comprises:

(A) coating cellulose of forming by wood pulp or Powdered wood pulp and cellulose acetate; the degree of acetylation of the occupied coating cellulose total amount 1.0-30% weight in wherein said wood pulp surface is that the cellulose acetate of 30-62% applies; and coating cellulose is biodegradable, or

(B) the fibrous or plain derivative of special fiber of deriving and from natural or regenerated cellulose or particle; acetylation surface portion wherein and non-acetylizad core form by described fiber of esterification or particle surface; and described cellulose derivative average substitution degree as a whole is 0.05-0.5; and described cellulose derivative is biodegradable

At coating cellulose described in the filtering material gross weight (A) or the described fibrous or shared ratio of the plain derivative of special fiber (B) is 50-100%.

16. the described tobacco filtering material of claim 15, by U.S. test and materialogy can D5209.91 with the burst size of carbon dioxide serve as indication measure 4 week degradation rate be the 40-100% of gross weight.

17. the filtering material that fiber that a tobacco filter, this tobacco filter are made of core and superficial layer or particle are formed is formed, the superficial layer of wherein said encirclement core is made up of cellulose esters, and described core is made up of non-esterified cellulose.

18. method of producing the tobacco filtering material, this method comprise (A) use cellulose esters to the fibrous or plain surface-coated of special fiber obtaining the painting method of coating cellulose, or (B) with organic acid and organic acid anhydride organic acid halide is handled natural in liquid phase or regenerated celulose fibre or particle to obtain the processing method of cellulose derivative.

19. the production method of the described tobacco filtering material of claim 18, wherein said painting method (A) is finished by making the plain ester of described fibrous or plain surface attachment of special fiber or adhering fibre, and dry gained coating cellulose.

20. the production method of the described tobacco filtering material of claim 19 wherein is with described cellulose esters dipping or spray that described fibrous or special fiber is plain to be adhered to described cellulose esters or stick to described cellulose surface.

21. the method for the described production of claim 18 tobacco filtering material, wherein in coating procedure (A), add the poor solvent of cellulose esters in the mixture of and cellulose ester solution plain to fibrous or special fiber, this solvent comprises water, aromatic hydrocarbons, aliphatic hydrocarbon, alicyclic and lam-oil.

22. the method for the described production of claim 18 tobacco filtering material, wherein in coating procedure, plain and mixture cellulose ester solution of fibrous or special fiber is a spray drying.

23. the method for the described production of claim 18 tobacco filtering material, wherein processing procedure (B) is carried out under the catalyst-free condition.